It used to be part of the game and was removed, according to the Minecraft Wiki "Classic 0.24_SURVIVAL_TEST and onward, there was a mob called 'Monster'," and it attacks you, before this it was called "Human" and it was passive, and spawned by pressing "g".
The screens of that it showed up few times i have two screens both are in attachments version 0.0.23_01
It used to be part of the game and was removed, according to the Minecraft Wiki "Classic 0.24_SURVIVAL_TEST and onward, there was a mob called 'Monster'," and it attacks you, before this it was called "Human" and it was passive, and spawned by pressing "g".
Now I don't know why the legs were in his body.
Hmm, creepy. Are you sure it is a monster? Could by an entity? 😁